Why High Definition digital audio matters

Today I found a very well-researched, well written article on xiph.org, that basically said that 16/44.1k should be enough for everybody.

I was slightly irritated, because I’m a firm advocate of DSD and 24/96k; having heard, and been able to spot the differences many times.

The author, Monty, argued that the human hear is unable to hear frequencies above 20k.

He cited the usual, well known studies on the subject, and was kind enough to include how they arrived at their conclusion.

And here is what he got wrong: The studies, upon close and unmerciful inspection, show only that the human ear is incapable of hearing sinus waves above 20k. Well, I’m not going to argue with that, we’re not bats, spot on!

If you know how a Fourier Transform works than you probably already know where I’m going here,  but if not, read on:

Any waveform, says Fourier, can be divided into sine and cosine waves of different frequencies, that combined yield the analysed waveform.

A square wave of 10k would have a 10k sine basic and then a 20k sine on top of that, and a 40k and so on, until it becomes a square wave.

Now if you chop off the frequency band at 20k, it just doesn’t look anything like a square wave, and doesn’t sound like one either.

But square waves are about as common in nature as sine waves, so that isn’t much of an argument in the favor of 96k sampling.

But, … transients: sharp, short spikes of audio, happen very often in nature and in music, particularly in modern music. And here 44.1k adds severe distortion, making placid hills out of sharp spikes, while also adding pre- and post ring to the spike, courtesy of oversampling digital anti-aliasing filters.

Now Monty goes on and cites a study by the AES that revealed candidates were only guessing whether something was 96k or 44k in an ABX blind test.

Why? Hard to tell, but reproduction equipment could be the main culprit here. Cheap amplifiers, headphones and loudspeakers often have very poor time-domain fidelity. Meaning? They smear a short, sharp transient all over the place. Making a better time-domain resolution undetectable.

David Blackmer, the eminent founder of DBX, wrote an excellent article on the subject in 1999. Here is a link.

To sum it all up: We need high-def digital, but we also need to focus more on time-domain fidelity. Here’s were the audio equipment industry is not delivering today, mainly because nobody cares. You get a pair of pretty flat frequency response headphones fo 5$, but headphones with great time-domain reproduction are hard to find and expensive.

For loudspeakers Meyer Sounds HD-1 come to mind, at 7000€ a pair…

Happy listening.


Hearing in a relative world – perception bias

I’ve been reflecting on the process of hearing, a lot, lately, and most of all about how we hear  frequency response. When do we percieve a song or a mix to be flat spectrum, when do we think a song is “phat” and when is it just bass-heavy?

I think the human brain strives towards presenting perfection to it’s user. We all know, that when listening to a strange sounding mix, it can become more agreeable over time, and sometimes the new sound then is our new frame of reference.

I think we can use that. If I want to make a track “phat”, I actually make it quite light on bass frequencies and then have very few elements that break that rule. For example let’s say I have a piano, some percussion loops and a kick drum and bass. I could make everything quite bass-light, except the kick, and some bass notes.

The ear adjust its response to the bass-light rest as “normal” and then gets surprised by the onslaught of the heavy kick-drum. Thus percieving the track as “phat”. Although it’s actually not.

Conversely, if I make too many elements “phat” in listening solo, I now have a bass-heavy track, and the brain “deletes” the extra bass information in presenting the track to me and so I percieve it as wobbly and not-phat.

I think fascinating mixes are all about building expectations, sonically, dynamically and structurally, and then breaking them in interessting ways.

Jazzfest Vienna, Staatsoper and Fernwärme

No started working at the Jazzfest Vienna this year. First was a Gig for 5k+ people at the Fernwärme Wien, Viennas main waste incineration plant that produces heat for over 200,000 households. You can see pictures of the enormous waste-storage cavern below. That was pretty spooky.

The stage location there was terrible, with one of the PA wings directly facing a massive steel and concrete wall just some 22m away, while the other PA wing adresses all of the 58m of audience basically alone.

I made use of the asymmetry in my PA design, aiming one side of the flown 8 MILOs just at the first 20m. The other side went the whole nine yards, with delay reinforcement of 6 M’elody after 25m. Much too short, but I wasn’t allowed any input into the stage and dealy tower planning, so I had to make the best out of a given situation. Still, the delay towers after 25m and just 4m high meant some rather bumpy coverage.

What went well was setting subs (2 times 4 700 HP) up in end-fired long-throw mode, that really fit very very well to the long-drawn narrow shape of the audience.

The people started coming in to see Viennese Soul/Funk superband Count Basic, who played at 36°C with 80{bebb06f271259ca942a7887f5eb25673b4b02ba69cbc6ed6f7a39064dc6657a8} humidity and sunlight directly into their faces. The stage got so hot, that lead vocalist Kelly Sae’s UM1P monitors shut down due to thermal overheating! The audience gathered in the shadow, populating a long and narrow strip, on the opposite side of the far-facing PA (duh!).

Now we are at the Vienna Staatsoper, one of the most famous opera houses in the world. I do monitors here, with Ronald Matky of Vienna Sound doing PA and FOH. PA here evolved during the last years. We’re extremely happy with a setup of 2 MSL4s with one 700HP per side for floor and first 2 balconies and 6 M’elodie per side for the upper 4 balconies. A MeyerSound Galileo controls everything,one PM5D for Mon and one for FOH. If the PA seems a little petite, please remember that we are in an opera house with supreme natural acoustics!

I love working in this building, which consists of an intricate maze of hallways and rooms, with a stage behind the stage that is some 30m high, and can be hydraulically lowered up to 20m deep! It really is a very special place. See some pics below and keep tuned for updates.

Home » Jazzfest Vienna, Staatsoper and Fernwärme

Jazzfest Vienna

Jazzfest 2012 Vienna Fernwärme Wien, Staatsoper, Arkadenhof.
8 MILOs Stage Left

WG Augsburg

Wise Guys Augsburg Dec. 2013.

donauinselfest 2012 – FM4 Stage – tech

Last weekend I did system tech for the FM4 Stage at the Donauinselfest in Vienna. For those of you, who don’t know about it, the Donaunselfest is one of Europe’s largest music festivals. It’s hosted on an Island in the Danube river in Vienna, lasts 3 days in June and attracts close to 2 million visitors each year.

The FM4 Stage is hosted by Austria’s most prominent independent-music radio FM4 and can accomodate close to 22,000 people if packed to the max. Acts this year included appearances by german hip-hop shooting star Marsimoto (he destroyed one M’elodie NF by kicking it off stage!), Samy Deluxe as well as austrian band Ja! Panik and a gig by the venerable Stereo MCs.

That gig got officially canceled by the authorities, but we let them play anyway, for 10 hot minutes, until the threats from the Viennese government got too severe… ha!

I did system tech, like I mentioned, working for Austrian PA rental company Vienna Sound. The PA System consisted of 2x 8 MILO speakers by Meyer Sound plus 10 700 HP and a total of 12 M’elodie as Nearfill (2), Outfill (2×3) and Center (4).

Monitoring was all Meyer Sound with 12 UM1P, 2 UM1C, 2 UPA, 2 PSW2s as Drumfill-Sub. I personally think the PSW2s really suck, since they always clip, even if just moderately confronted with Kickdrums. Unless you cut out all the sub-information, which is okay, since the PA subs were located under the front of the stage and clearly felt on top.

2x 8 MILO were enough for the natural arena in which the stage is located, but I could have used 2 more per side, budget wouldn’t allow it though. The entire PA was controlled by MeyerSounds excellent Galileo 616, I just love those filters!

I arrayed the 700s in an end-fired variety with 2×4 doing an end-fired subwoofer array for FOH sub pleasure, which most of the engineers appreciated, especially Samy Deluxe’s wonderful Tony Robbins, whose birthday coincided with the gig! The other 2 were there to spread the love around. But still, for a stage of that size 10 are a fraction too little and I had to neglect the outer areas of the arena, in favor of FOH and center. Especially those first 10m got maybe a little too much bass-love. But they were dancing all right!

What worked very well was to have a center cluster that was fed by a send of its own off of the PM5D at FOH. Most engineers followed my suggestion to just put the vocals in there.

I then summed this mix into the near and outfills and had great vocal intelligibility even in the first rows. This one’s a definite keeper.

The team was: Raimund Bretterbauer on Monitor System and Stage, Me as FOH Systech and planning the PA setup.

Below some pics. If you have any questions feel free to post here or write me.







my shoebox NAS – update

So I installed Windows 8 as an OS, the Consumer Preview, to be exact.

I’ll update it to an RC as soon as one becomes available. The installations was a breeze, and I haven’t looked back ever since. Setting up an FTP-Server was easy and hassle-free thanks to FileZilla Server, Media Player does UPnP Streaming and Filesharing is deliciously easy thanks to Win7 Homegroups.
Administration is beautiful and comfy with a Remote Desktop Connection, and hey, it even displays the gorgeous new Metro interface.
SoI’m quite happy about my OS choice.
Since I didn’t install a fan – yet – and my NAS is made out of paper, I’m slightly worried about combustion. But so far in-the-box temeperature hasn’t risen above 45° Celcius, way too low to burn paper (232 °C).

But I’m going to get a fan anyway.

building the perfect NAS – in a shoebox

So, I finally got arround to assembling everything that I bought for my perfect NAS.

I assembled everything in a shoebox, just for fun, looks terrific, see pics below.

Everything gets held to the shoebox by cable ties, and since cardboard tears very easily I reinforced it with duct tape… ha!

I’m using 2 Harddisks, 1 is a 1,5 TB Samsung 3,5″ and a 80GB 2,5″ from the former laptop of my current girlfriend, that holds the OS.

I decided on using 2 HDs because I want to be able to change OS easily, and that may include partitioning the HD.

So first I installed Debian 6. It worked okay, but I’m not a Linux guru, and so configuration always took more time than I felt comfortable spending.

And now… I’m using Windows 8….. ha!

When I first got my laptop (Lenovo X220) I wanted to install Linux. Ubuntu, or Fedora. But the battery live was half of what other people reported on Win 7. This was due to a bug in all Linux kernels past 2.6.39 (see here and here).

While researching on that topic I found out that Win7 has super energy-efficient drivers, mainly because MSFT dictates clearly hwo drivers will interface with hardware to the OEMs and hardware manufacturers. But, hey, in some cases monopolies can be beneficial.

And since energy is a huge issue with a NAS, that’s running 24/7, I decided to go with Windows. Also I’m much more knowledgeable with administering Windows, so that’s another plus.

As for longtime running stability, I just fired it up, so I’ll let you know.

in search of the ultimate Headphone

Since I’m working in the field of audio recording and reproduction in its various forms for more than 12 years now, I often find myself in the need of an excellent headphone. Checking signals, tracking, mixing, or just listening to music while traveling, I often need headphones.

Working in studios with excellent monitoring for years, my demands are quite high, and so far I haven’t been fully satisfied.

But let me tell you my story here:

I started out with Sennheiser HD 250 II headphones, which were excellent, although really large. I used them for 8 years and loved them. Then I lost them, tragically, at a ball in Viennas City Hall I was working at.

Next came my quest for headphones with, what I call, active isolation. Bose QuietComfort 3 were first. They did an excellent job in noise cancellation, to the point where plain rides were really quiet. But the actual headphone, while quite pleasant to wear, sounded really, really bad. Individual notes on piano sonatas (like Rubinstein playing Chopin) jumped out of context, sometimes distorting (and I don’t listen very loudly).

So I sold those on eBay, and bought a pair of Monster Beats Studio by Dre, that I imported from the US (They weren’t available in mainland Europe at the time). Excellent headphone. Fantastic noise cancellation, especially in the lows (Bose were better in the mids and highs). The sound was great too. But: After about 3 months use, the right earpiece sometimes made mechanical noises on certain notes. It wasn’t a linear process. Listening to uncompressed live signals would trigger the noise more often than compressed CD playback. Also the whole soundscape seemed a little hyped and strained.

At the same time I got a second piece of headphones: AKG K702. I had the K701 before for home listening and the 702 were altogether better. A brilliant, lively headphone, especiall with a tube headphone amp. Just one flaw: Little bass. Maybe I’m too used to closed headphones, but the AKGs didn’t cut it for me in that regard.

So, the quest continues, with me selling the Dres and buying Beyerdynamic DT-150s. Soundwise the best headphone I had so far. Perfect, in my opinion. Pronounced midrange, tight bass, not too bright like Sennheiser HD 800s or the top-of-th-line Ultrasones. Just right. Problem here: they clamped down on my head pretty hard, hurting me after 30 minutes of wear, which happens, on planes and on trains.

Sold those and just today got a brand new headphone: Aiaiais TMA-1. A danish manufacturer. The pretiest headphone so far. Clean, understated design. No logos, no gimmiks.  A beauty. Sound: Voices sound great, fantastic even! But: no highs. And I mean: no top end, period. I should have known reading the frequency chart in some reviews. So, I’m sending them back today, and still searching for the ultimate headphone. Any suggestions? Shure’s new line is supposed to sound great! I’ll let you know.

building a home WFS system

I’ve been into spatial audio and especially Wave Field Synthesis, ever since my neighbor Simon Katzböck introduced me to the concept in Mörbisch, some years ago now. There, at the Seefestspiele, I was stunned to see how well it worked, how the voices seemed to originate from the singers, not the PA, and how realistic the LARES system there made the orchestra feel like it would in a concert hall. Mörbisch doesn’t feature a full fledged WFS installation, it’s more like a high order Ambisonics system that is quite unique and proprietary with a lot of fascinating technology supplied and programmed by the Fraunhofer Institute.

So, since no WFS installation is available in Vienna to play around with, I decided to build my own. I went for the minimum design first, to get some experience, and also to keep the cost (A/D converters especially) down. 16 channels would do for a first. I’m quite proud of how low I have been able to keep the costs till now. Here’s what I use:

  • 16 Visaton K50 speakers (250 Hz to 12kHz).
  • 8 2x 3W 5V powered amp boards fromSingapore, that I got on EBay (see photo below).
  • 2 8A 5V power supplies, also from Singapore, also source via EBay.
  • RME Multiface I that a friend lent me, for 8ch analog out, plus ADAT out.
  • Behringer UltraGain 8000 for additional 8ch.
  • a wood box with padding inside as a cabinet.

Total cost so far: less than 300€. I’m just assembling the whole shebang, and very excited to hear the first tones. On the software side I’m using PureData as a signal source and Marije Baalmans sWONDER WFS software for rendering.

Both are open source. PureData and SuperCollider will be running on my laptop (Lenovo X220 8GB i5, Win 7) and sWONDER on a Core2Quad PC with Debian 6 installed. Below some photos that I took so far, and as always, keeping you posted on the progress.

custom ROM for my HTC ChaCha pt2

So, after some fretting, and woeing why I hadn’t backed up my original ROM I finally got to the heart of the issue. The SuperDroid 1.0 ROM I installed on my ChaCha comes with A2SD baked in. A2SD or App2SD is a beautiful little app, that moves all of the apps to a ext3 partition on your SD, that you first create on with ClockworkMod (here’s a nice How-To). The problem here: my SD is a very, very cheap, very, very slow SanDisk microSDHC. So Apps like Messaging, Phone and so on take a very long time to load, making my phone very sluggish.

I deactivated A2SD with the GUI that you can download on Google Play and installed Link2SD, a beautiful tool that let’s you put programs on an ext3 partition of your SD and then creating symbolic links in Androids app directory. The advantage of partitioning your SD is, that, once you select the Disk Drive option when USB connecting, your phone only ejects the FAT32 partition of your SD card and not the ext3 partition, thus keeping all of your apps useable.

Now my phone is working really nicely, has lots of features it didn’t have before, like Titanium backup, or SSHDroid and AdFree. Next Step will be getting a fast SD card and then reactivating app2SD.

custom ROM for my HTC ChaCha

I really like my ChaCha, but one thing I got really fed up with is that it runs out of memory very often, so I can’t install some apps, like Instagramm or can’t update to the newest version of Google Maps. So after researching it a bit, I decided to install a custom ROM, SuperDroid, that would allow me to remove some of the built-in apps like Facebook and add a few others like Link2SD.

So I began, and altough my phone was S-ON, for whatever that means, which supposedly makes it more difficult to root it, I succeeded by doing this: (I exclude all the missteps and stepbacks, so it seems like one seamless, easy process, which, believe me, it was not)

  • Converted a microSD card to a gold card, so I can flash another version of the ROM, than the one, that I had.
  • Installed the newest HBoot from HTCs Dev site. (RUU_blabla.exe, before the actual unlocking begins)
  • Unlocked the Bootloader, as discribed in great detail on HTCs Dev site.
  • Installed CWM as described in this post, the XDA method failed me.
  • Installed my SuperUser.zip as described in same post.
  • Installed the SuperDroid ROM as described here.

So, I’ve been using it for a day now, and… IT COMPLETELY SUCKS!!! The phone is slow, drains battery, SMS take 2 minutes (yes that’s 120 seconds) to load, and contacts don’t display correctly!

Unfortunately it’s not easily possible to reinstall the stock ROM, since the HTC Rom Updater won’T flash, for security reasons. So, I’m currently searching for someone who was smart enough to backup their stock ROM before flashing.

Keeping you posted.